Referring to FIG. 1, a gas container 1 includes a bag 4 and a mouth 2. The mouth 2 is made of polyoxymethylene so as to exhibit adequate rigidity. Since polypropylene does not dissolve in alkane and prevents aluminum from oxygenation, an inmost layer 3 of the bag 4 is made of polypropylene. However, gas often leaks between the mouth 2 and the inmost layer 3 of the bag 4 because of poor connection between them.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.